Generation and Evaluation of KSHV VLPs as Vaccines

描述(由申请人提供)：本提案是根据ARRA在开发艾滋病相关恶性肿瘤疫苗的探索性研究的重大机会(RC2机制)下宣布的RFA-OD-09-004而提交的。这是为了刺激预防或治疗性癌症感染性原因疫苗开发的早期创新研究努力。卡波西肉瘤(KS)是艾滋病流行中最初定义的机会性感染之一，当时这些高度血管生成的皮肤病变最初出现在纽约和旧金山的年轻男同性恋者身上，表现为侵袭性的、通常是播散的形式。1994年，经典和流行性KS都被发现是由一种以前不为人所知的人类疱疹病毒引起的，这种病毒被称为卡波西肉瘤相关疱疹病毒(KSHV)，有时也被称为HHV8。今天在南部非洲，由于艾滋病毒传播到几乎普遍感染KSHV的人群中，KS已成为所有肿瘤中最常见的。相比之下，在西方国家，KSHV感染是非常罕见的，除了在艾滋病患者中有混杂的生活方式因素，在那里这种情况与艾滋病毒诱导的免疫抑制一起产生KS的频率很高。幸运的是，HAART和相关疗法的使用减少了KS的问题，但仍有一部分患者具有稳定的重组免疫功能，其中KS再次出现，并随着时间的推移变得越来越无反应。我们认为，应该认真考虑将KSHV预防性疫苗作为在西方国家控制KSHV感染的潜在方法，未来也可能在非洲进行控制。然而，对KS或非KS患者对KSHV感染的免疫反应知之甚少，以前疫苗似乎并不具有吸引力，因为这种病毒的大小和复杂性，以及作为一种形成肿瘤的病毒，病毒基因组和癌基因必须缺失或移除。基于最近预防性HPV亚单位疫苗预防宫颈癌的成功，以及流感等小病毒的病毒样颗粒(VLP)可以有效地诱导各种免疫反应的证明，现在需要重新评估其他艾滋病恶性肿瘤的疫苗前景。在这里，我们提出了初步的探索性步骤，既开发了一种基于无DNA VLP的KSHV/KS预防性疫苗，又开发了一种革命性的高通量全球蛋白质组方法，用于测量KSHV阳性患者中的病毒抗体和中和反应，以及VLP疫苗接种后的反应。这些将在实验性接种的小鼠以及现有的艾滋病和KS患者血清集合中进行评估。全球蛋白质组方法的另一个优点是不仅可能提供关于新的KSHV抗原和表位的许多新的数据发现，而且可能被用作所有相关患者的体液免疫和T细胞介导的免疫的泛疱疹病毒免疫评估芯片。 公共卫生相关性：叙述：该项目响应了RFA OD-09-004关于开发艾滋病恶性疾病疫苗的早期探索性研究。我们建议尝试在昆虫细胞培养中组装无DNA病毒样颗粒(VLP)，作为预防由疱疹病毒KSHV引起的卡波西肉瘤的潜在疫苗。对这些实验性VLP的免疫反应将通过开发一种创新的全球高通量分析方法的第一步进行评估，该方法用于识别和测量病毒蛋白，作为艾滋病患者对KSHV和其他人类疱疹病毒的体液(中和抗体)和T细胞介导的免疫反应的目标。

DESCRIPTION (provided by applicant): This proposal is being submitted in response to the Announcement RFA-OD-09-004 under ARRA Research Grand Opportunities for Exploratory Research in the Development of Vaccines for AIDS-Associated Malignancies (RC2 mechanism). This is designed to stimulate early stage innovative research efforts in either preventative or therapeutic vaccine development for infectious causes of cancer. Kaposi's sarcoma (KS) was one of the original defining opportunistic infections in the AIDS epidemic, when these highly angiogenic skin lesions first appeared in an aggressive often disseminated form in young gay men in New York and San Francisco. In 1994, both classic and epidemic KS were found out to be caused by a previously unknown human herpesvirus called Kaposi's Sarcoma Associated Herpesvirus (KSHV or sometimes HHV8). Today in Southern Africa, KS has become the most prevalent of all tumors because of the spread of HIV into a population that was already nearly universally endemically infected by KSHV. In contrast, in Western countries, KSHV infections are very uncommon, except in AIDS-patients with promiscuous life-style factors, where this combined with HIV-induced immunosuppression produces KS at high frequency. Fortunately, the use of HAART and related therapies has reduced the problem of KS, but there is still a subset of patients with stable reconstituted immune function, in which KS reappears and becomes increasingly non-responsive over time. We believe that preventative vaccines against KSHV should be seriously considered as a potential way to control KSHV infection in Western countries and possibly in future in Africa also. However, little is known as yet about immune responses to KSHV infection in either KS or non-KS patients, and vaccines did not appear attractive previously because of the large size and complexity of this virus, as well as the fact that as a tumor forming virus the viral genome and oncogenes would have to be absent or removed. Based on recent success with prophylactic HPV subunit vaccines to prevent cervical carcinoma, and the demonstration that virus-like particles (VLP) of small viruses such as influenza can be effective in inducing a variety of immune responses, the vaccine prospects for other AIDS malignancies now need to be reassessed. Here we propose initial exploratory steps to both develop a DNA-free VLP-based preventative vaccine for KSHV/KS, and to develop a revolutionizing high-throughput global proteome approach to measuring viral antibody and neutralization responses in KSHV-positive patients with and without KS, as well as the responses induced by VLP vaccination. These will be assessed in experimental inocculated mice, as well as in existing collections of AIDS and KS patient sera. The global proteome approach has the additional advantage of not only likely providing much new data discovery about novel KSHV antigens and epitopes, but also potentially of being used as a Pan-herpesvirus immune assessment test chip for both humoral and T-cell mediated immunity in all relevant patients. PUBLIC HEALTH RELEVANCE: Narrative: This project responds to an RFA OD-09-004 for early exploratory research on the development of vaccines for AIDS Malignancies. We propose to attempt to assemble in insect cell culture DNA-free virus-like particles (VLP) as potential preventative vaccines against Kaposi's sarcoma, which is caused by the herpesvirus KSHV. The immune responses to these experimental VLP will be assessed with the first steps in development of an innovative new global high-throughput assay approach for identifying and measuring viral proteins as targets for humoral (neutralizing antibodies) and T-cell-mediated immune responses to KSHV and other human herpesviruses in AIDS patients.